'92 Festiva with 1.6L SOHC

[AndreyB]

However I don't see a black wire connecting the STM GND to the vehicle - battery terminal.

If that's the case then it would explain a lot. Nice catch! If that's a catch

[skeeters_keeper]

Indeed, I did not have a ground to the battery!

After some more messing around, adding a ground to the battery and a resistor inline with the signal (which is 5v btw) this is what I have at a fast idle:

TachScreenShot3.tiff

And with the engine revved a bit:

TachScreenShot4.tiff

And here is what the stock festiva disty looks like inside:

FestivaDisty.jpg

Oh, and Russian it still says firmware NA - so I guess I need to update my firmware on the board

[AndreyB]

My Mozilla does like your .tiff images. As in cannot show them

Update: my Explorer was able to show them. Can you please zoom in so that it shows say 6 waves? Anyway, that's some real progress here!
I still see some noise - these lines inside the waves - but we are close.
I have to step see if my Festiva would fire up with a 2000 Miata head, ttyl. Let's thank Jared for the GND hint

[AndreyB]

PS: looking at this dizzy I see a two channel signal, do you have another wire? Can you hoop up the secondary channel the same (your op-amp is probably dual-channel anyway) and I will need your log files to figure out the exact trigger shape. Good progress!

PPS: on another thread you were concerned about boards getting obsolete. They do not get obsolete - you can still use the older individual modules, the firmware would always support them.

[kb1gtt]

For cartoon like pictures, I would like to suggest .png it will have good compression while keeping a good level of detail and pretty much everything can view it. When it comes to pictures from a camera or similar with many different shades of color, I would suggest a .jpg, it's a lossy compression, but generally good enough as your eye will blend things together. I also can not see the .tiff on my linux Chrome. I'll go look at them with a windows machine and IE, but there are sure to be others with the same problem.

I'm also likely a culprit about creating a feeling like things might go obsolete. I'll always push for changes as I tend to feel things can always be better. It has been working well here as russian has been drawing lines in the sand and making things usable. Getting boards now should work with your setup and I don't see them ever being obsolete.

[kb1gtt]

Oh, also what op-amp did you use? If you need some help getting this working on the second channel, I can offer some help, perhaps a pencil sketch or something like that. Let me know if you need a sketch.

[puff]

Didn't know it was tiff - works okay in my Safari on a Mac

[puff]

rpm figures are so nice!

[skeeters_keeper]

Sorry about the .tiff, that's what Grab (the screen capture program) defaults to. I usually convert them to jpg but got lazy this time...

I am using an OPA2340, but I also have a few MCP6002 as discussed in the "DIY Hall input" thread.

A pencil sketch of using two channels would be great - would the second channel feed another input pin on the stm?


As far as boards going obsolete - I'm not saying that they aren't still functional, but they are no longer necessary if you have the frankenstein board. So the time/money spent on them was basically a "waste" because you're no longer using them once you have a newer version of the board. Similarly V.1 of frank may work but I'm sure it will have room for a few improvements, maybe integrated BT or power supply etc, so if I buy it now and you release v.2 in a few weeks... well, you see what I'm saying. I realize things will always change and you can't wait forever for the "final" version because with tech there is no such thing, but I'm sure this is a large part of the reason you aren't seeing more people buy the boards right away.
I do plan to order the board in the next few weeks... I just spent too much $$$ on my rocketry hobby this month!

[skeeters_keeper]

The sensor has a 4 pin plug with only three wires, 12v, gnd, sig.

I was hopeful that the other pin was there and ready to be used - so I tore the disty apart a bit further and there is nothing on the other pin :/ only one LED and it is inline with the four smaller slots, the spot for the other LED (in line with the one slot per revolution) is empty. Since this car is batch fire from the factory I guess they didn't need to know which cyl it was on.
So if I understand correctly that means there isn't enough information for COP or sequential injection and I'll need to either add a trigger wheel on the crank or maybe fit an aspire distributor, which has both signals.

[puff]

installing trigger wheel on the crankshaft won't provide you such information, but will probably increase accuracy?
so do both, and request a feature, so that close circuits in the disty give signals for a certain sparks for instant start

[puff]

oh, it's probably contactless. one more option is to fit your own, custom-cut slotted plate, with, say, 7 usual size slots an one twice as larger slot for 0º.
one more thing, which I can't understand is that on the upper screenshot you have somewhat 6 impulse per rotation, and on the lower screenshot, with increased rpm you have a different number of impulses? weird.

[kb1gtt]

Ah 5V, with a J927 optical sensor. Hmmmm, why can't I find a pin out or schematic for this sensor? Is there a snippet from a service manual or something that could help?

Looks like the noise is consistently on the falling edge. I think I know why this is, but I'm trying to find a reference schematic. Do you know if the sensor's internal wiring is similar to this http://m.eet.com/media/1093612/0307feat2fig2.gif

If so do you know what the internal pull up resistor is? I think it is done that way, and if it is, I would suggest a 2k to 5k resistor between the green signal wire and black GND. That will probably fix the issue, if not, I have some other suggestions, but lets try that one first as it's easiest.

[puff]

btw, for positioning purposes you could just install a photon-coupled transistor against the larger inner slot.

[skeeters_keeper]

Here are two more shots of the sensor from the distributor.

FestivaCPS1.jpg

FestivaCPS2.jpg

I found some info in one of my books on the CPS:

CPS_info.pdf

It sounds like the BP (1.8DOHC) should have a similar/same sensor but with both LEDs - great, I have one on an engine stand!

[AndreyB]

Would be funny if a piece of an Aspire dizzy would bolt on - http://rusefi.com/articles/tachometer/1995_aspire_distributor_3.jpg

[AndreyB]

So, what do you we call your engine configuration file? Mazda 323?

[skeeters_keeper]

Here it is:

BP_disty1.jpg

and inside:

BP_disty2.jpg

No such luck :/

This one is a Mazda BP. I have another BP in a car outside - from an Escort GT, so maybe that one is optical. However I ran out of daylight. Even if it is optical I'm not sure I need the second sensor yet... but still, it'll be interesting to see if I can get it from an escort disty.



I'm not sure if any of that info helps you know whats going on inside my sensor, and I didn't try it with the resistor between the signal and gnd yet. Hopefully I can try it tomorrow night because I'm going to be gone most of the day tomorrow.

[skeeters_keeper]

Would be funny if a piece of an Aspire dizzy would bolt on - http://rusefi.com/articles/tachometer/1995_aspire_distributor_3.jpg

An aspire dizzy will bolt on! I don't have one right now unfortunately... I did last week. But I don't think my mazda ECU will like it and I need to keep this car on the road :p

[skeeters_keeper]

So, what do you we call your engine configuration file? Mazda 323?

90-93 Festiva (1.3l SOHC) and 90-94 mazda 323 (1.6l SOHC) use the same general engine management. Meaning, you can run the 323 engine on a Festiva ECU. The distributors are the same part number, VAF can be interchanged (although the 323 VAF is slightly different) etc. Almost exactly the same engine just one is bored out a bit. Some people have run their B6 in a festiva on festiva ECU for years.

So I think you can call it either Festiva or 323, because with a small amount of tweaking it will work for either.

[kb1gtt]

Yes that snippet helps. It notes this works very similar to a hall sensor, and almost all hall sensors are low side transistors with a pull up resistor. So yours is very likely to be the same setup as the picture I posted above.

No worries about the the series resistor on the signal wire. I suggested that just to play it safe. However with 5V and if it works, then your OK. Basically that resistor is only there to limit current if your signal exceeds 5V.

Do you have a multi-meter that can measure around 10mA of DC current? Can you measure the current in either the power wire or the ground wire for the optical sensor? Can you tell me what it reads both when the op-amp LED is bright, and when it is dim. Also what is the voltage? I know it's 5V, but is is 4.9 or other?

Once I get those readings, I think I'm going to have you change how you have the op-amp wired. Right now it's a voltage follower, but I think we want to change it to a comparator. I think that's going to be the best way to remove the noise.

[skeeters_keeper]

A little more info incase it will help anyone else down the road:
The BP came with two different styles of distributor. T2T52471 and T2T52471B
T2T52471 uses optical sensors and has Mitsubishi ignition module J925 http://tinyurl.com/mqaotgt

T2T52471B is the one I have pictured above (hall sensor?).

It appears that you can put that ignition module into the festiva/323 distributor and now you will have use of the fourth pin. I have not tested this yet!! Another option (if you are going to COP) is to use a miata cam pos sensor, which has the same internals but no distributor cap/rotor.


Jared, I will try to play some more tomorrow night if I can, and I'll get back with the results asap

[AndreyB]

I've added a default config for this trigger shape, please activate it
set_engine_type 11
once you get the latest firmware (20140308)
See also http://rusefi.com/wiki/index.php?title=Manual:Engine_Type

I am hoping to see correct tachometer reading - that's once the noise issue is resolved completely.

[kb1gtt]

When you get around to trying this on the engine again, do you want to consider a change in schematic? I think you'll have better results with the attached schematic. If you need help with getting that into the breadboard layout, let me know your op-amp and I'll draw it up a bit more like it would be done on the breadboard. R1 would want to be something like 5k, and R1 would want to be something like 1k. Basically you want to hold the - side of the op-amp at around 1V to 2V, then the op-amp output will swing as the signal crosses that voltage.

[skeeters_keeper]

Do you have a multi-meter that can measure around 10mA of DC current? Can you measure the current in either the power wire or the ground wire for the optical sensor? Can you tell me what it reads both when the op-amp LED is bright, and when it is dim. Also what is the voltage? I know it's 5V, but is is 4.9 or other?

I tried getting these readings tonight - I hooked up one DVM inline with the GND on the sensor to measure the current and another one between the signal pin and ground (so I could see when the trigger was triggered). But things did not work as I expected - with the key "on" (and the coil wire disconnected, so I couldn't accidentally fire a cylinder) I turned the engine over by hand - and I never got a current reading. The DVM on the signal wire was reading 9.3v and stayed the same as I turned over . My battery had a full 12.5v. When the engine was running the other day I had pretty steady ~5v so I don't understand that.


Russian - I've got the new firmware and now it says Mazda 323

[puff]

probably you don't need to startthe engine with a key, you need to rotate the crank by hand just a bit, by several degrees so that the led in youd disty is against the slot, and then measure all the voltage and currents

[kb1gtt]

A couple quick thoughts, have you verified the fuse is OK in your DMM? Try using a separate meter if you have a separate meter, do a beep test or check for 0 ohms instead of open circuit across your current reading meter's leads. I've seen several people take a voltage reading, then roll the dial across the current readings to turn a meter off or something like that. When they cross the current readings it blows the fuse and they don't know it. So I would say first things first. lets make sure you DMM fuse is still good. The next thing, this was the optical sensor correct? Not a hall sensor, and not a variable reluctor? A variable reluctor won't work until you get some RPM's going, most hall's will work down to 0 RPM, but not all. Some have internal circuitry but I would not expect this from an OEM device.

[skeeters_keeper]

puff, that's what I did - rotated the engine by hand (but with the key "on" so that I had power to the sensor)

Good idea to check the fuse... it worked fine last time I used it but it has been a while. And yes, it is an optical sensor, same as the one I took pictures of.

[puff]

just came to my mind: could that noise (that was the problem, right?) be caused by the reflection of light? consider using the black water-proof felt-tip pen to make that slotted disk less shiny

[kb1gtt]

I don't think the sensor is doing anything wrong. I think it's an electrical issue. The STM will trigger at around .6 to .8V ish. See below picture, and notice the round nature that's close to .7V, also notice in the other picture the ringing on the bottom side. You could have either one of these issues, or both of these issues. The result would cause a couple 1's and 0's to be triggered in software. This is why I suggest the comparator, as it would trigger the input at a higher voltage. As an alternative, you could use an actual compariator, as those have some hysteresis which helps prevent the ringing. However I know you have an op-amp and it should work good enough.



Or it might look something like this